Testosterone and Neural Function

• Status: Recruiting
• Trial end date: 2026-03-31
• Target enrollment: 0
• Participant gender: Male

Summary

Spinal cord injury (SCI) disrupts the nerves controlling movement, along with those that regulate functions like heart rate and blood pressure (known as the autonomic nervous system, or ANS). Testosterone (T) plays a significant role in brain health and ANS reflex function in non-neurologically impaired men. However, little is known about the relationships between T, nerve function, and ANS dysfunction after SCI. Interestingly, up to 60% of men with SCI exhibit persistently low T concentrations, which may worsen nerve and ANS dysfunction. In uninjured eugonadal people (normal physiologic range of serum T concentrations), a single pharmacologic dose of intranasal T has been shown to quickly improve nerve function, but no study has evaluated if T administration alters nerve and ANS function in men with SCI. Herein, the investigators will conduct the first study to test how a single dose of intranasal T impacts motor and ANS function in this population.

• Phase: Early Phase 1
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: VA Office of Research and Development
• Treatments: Methyltestosterone; Testosterone; Testosterone 17 beta-cypionate; Testosterone enanthate; Testosterone undecanoate

Criteria

Inclusion Criteria:

• Age 18-80 years

• Time since injury (TSI) more than 12 months

• Traumatic or non-traumatic SCI

• American Spinal Injury Association (ASIA) Injury classification Scale (AIS) A, B, C, or D

• Stable prescription medication regimen for at least 30 days

• Not currently receiving pharmacological treatment for hypogonadism

• Must be able to commit to study requirements of 3 visits within a 30-day period

• Provide informed consent

Exclusion Criteria:

• Extensive history of seizures

• Ventilator dependence or patent tracheostomy site

• History of neurologic disorder other than SCI

• History of moderate or severe head trauma

• Currently receiving treatment for hypogonadism

• History of allergy, hypersensitivity, or other significant adverse reaction to testosterone replacement therapy

• Significant cardiovascular disease or cardiac conduction disease

• Active psychological disorder

• Moderate or severe brain injury, stroke, tumor, multiple sclerosis, or abscess

• Recent history (within 3 months) of substance abuse

• Pressures sores stage 3 or greater

• Active infection

• Frequent severe migraines

• Recent history (within past 6 months) of recurrent autonomic dysreflexia, defined as a syndrome of sudden rise in systolic pressure greater than 20 mm Hg or diastolic pressure greater than 10 mm Hg, without rise in heart rate, accompanied by symptoms such as headache, facial flushing, sweating, nasal congestion, and blurry vision (this will be closely monitored during all screening and testing procedures)

• History of implanted devices with electromagnetic properties: brain/spine/nerve stimulators, aneurysm clips, ferromagnetic metallic implants in the head (except for inside mouth); cochlear implants; cardiac pacemaker/defibrillator; intracardiac lines; currently increased intracranial pressure; or other contraindications to brain or spine stimulation

• Use of medications that significantly lower seizure threshold, such as amphetamines, neuroleptics, dalfampridine, and bupropion.